a Herein, a novel strategy has been proposed to fabricate graphene quantum dots (GQDs) infilled titanium dioxide (TiO 2 ) nanotube arrays (NTAs) hybrid structure for dye degradation of methylene blue (MB) under UV light (365 nm) irradiation. GQDs are infilled inside the TiO 2 NTAs (via anodic oxidation of a Ti sheet) through an impregnation method. Moreover, the morphology of the TiO 2 NTAs is well maintained after filling the GQDs inside, which is favorable for mass transfer. The peak intensity of photoluminescence (PL) spectra of the GQDs infilled TiO 2 NTAs catalyst is lower than that of annealed TiO 2 NTAs and a strong violet UV emission is obtained at 387 nm upon 252 nm deep UV excitation. The photocatalytic activities of the TiO 2 NTAs are evaluated in terms of the efficiencies of photo-decomposition and adsorption of MB in aqueous solution under UV light irradiation, after the impregnation of GQDs inside the TiO 2 NTAs. The highly-efficient photocatalytic activity is attributed to the broad absorption in the visible wavelength region, large photo-induced charge separation through the transfer of photogenerated electrons from the TiO 2 NTAs to GQDs, as well as the strong adsorption capacity of the GQDs to MB molecules. Thus, the GQDs infilled TiO 2 NTAs could be widely used as a photocatalyst for treating organic contaminants in the field of environmental protection.

We report a design and fabrication strategy for creating an artificially stacked multilayered optical filters using a thermal evaporation technique. We have selectively chosen a zinc sulphide (ZnS) lattice for the high refractive index (n = 2.35) layer and a magnesium fluoride (MgF2) lattice as the low refractive index (n = 1.38) layer. Furthermore, the microstructures of the ZnS/MgF2 multilayer films are also investigated through TEM and HRTEM imaging. The fabricated filters consist of high and low refractive 7 and 13 alternating layers, which exhibit a reflectance of 89.60% and 99%, respectively. The optical microcavity achieved an average transmittance of 85.13% within the visible range. The obtained results suggest that these filters could be an exceptional choice for next-generation antireflection coatings, high-reflection mirrors, and polarized interference filters.

A facile method to produce conformal coated reduced graphene oxide (rGO) on vertically aligned titanium oxide (TiO2) nanotubes three dimensional (3D) arrays (NTAs) is demonstrated for enhanced field emission display applications. These engineered nano arrays exhibit efficient electron field emission properties such as high field emission current density (80 mA/cm2), low turn-on field (1.0 V/μm) and field enhancement factor (6000) with high emission current stability. Moreover, these enhancements observed in nano arrays attribute to the contribution of low work function with non-rectifying barriers, which allow an easy injection of electrons from the conduction band of TiO2 into the Fermi level of reduced graphene oxide under external electric field. The obtained results are extremely advantageous for its potential application in field emission devices.